Smalleye Squaretail, Tetragonurus cuvieri Risso, 1810

Scientific name: Tetragonurus cuvieri
Alternative name/s:
Raven Fish, Squaretail
Smalleye Squaretail, <i>Tetragonurus cuvieri</i> Click to enlarge image
A 47 cm long Smalleye Squaretail from the fish collection (AMS I.38070-002). Image: Stuart Humphreys
© Australian Museum

Fast Facts

  • Classification
    Genus
    Tetragonurus
    Species
    cuvieri
    Family
    Tetragonuridae
    Order
    Perciformes
    Class
    Actinopterygii
    Subphylum
    Vertebrata
    Phylum
    Chordata
    Kingdom
    Animalia
  • Size Range
    The Smalleye Squaretail grows to 70cm in length.

Introduction

The Smalleye Squaretail can be recognised by its distinctive jaws, scalation and body form. It has a widespread distribution in most world oceans.

Identification

The Smalleye Squaretail can be recognised by its distinctive jaws, scalation and body form. The lower jaw is very stout and has a single row of fan-like teeth. It is almost totally concealed by the upper jaw when the mouth is closed. The upper jaw has small pointed teeth in a single row. When viewed from the front the mouth opening is diamond-shaped.

The species has a long, slender body that is rounded in cross-section. There are small, ridged scales arranged in spirals around the body. The caudal peduncle is rectangular in cross-section and has two lateral keels on both sides.

Adult Smalleye Squaretails are uniform dark brown to black. The juveniles are grey above and whitish below. This is probably an adaptation to the deepwater habitat of the adult and the surface habitat favoured by juveniles.

Smalleye Squaretail, Tetragonurus cuvieri
Head of a 47 cm long Smalleye Squaretail from the fish collection (AMS I.38070-002). Image: -
© Australian Museum

Habitat

Adults live in continental slope waters at depths from 500 m to 600 m.

Distribution

It has a widespread distribution in most world oceans. In Australia, the Smalleye Squaretail is recorded from New South Wales, Victoria and Tasmania but probably occurs in deep waters off all southern Australian states.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.

Feeding and diet

The species eats jellyfish and salps.

Danger to humans

At certain times of the year it is reported to be poisonous.

References

  1. Gomon, M.F. in Gomon, M.F, C.J.M. Glover & R.H. Kuiter (Eds). 1994. The Fishes of Australia's South Coast. State Print, Adelaide. Pp. 992.
  2. Hoese, D.F., Bray, D.J., Paxton, J.R. & G.R. Allen. 2006. Fishes. In Beesley, P.L. & A. Wells. (eds) Zoological Catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia. parts 1-3, pages 1-2178.
  3. Last, P.R, E.O.G. Scott & F.H. Talbot. 1983. Fishes of Tasmania. Tasmanian Fisheries Development Authority. Pp. 563.
  4. May, J.L & J.G.H. Maxwell. 1986. Field guide to Trawl Fish from Temperate Waters of Australia. CSIRO. Pp. 492.